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Gq protein or Gq/11 is a heterotrimeric G protein subunit that activates phospholipase C (PLC). PLC in turn hydrolyzes phosphatidylinositol (PIP2) to diacyl glycerol (DAG) and inositol triphosphate (IP3) signal transduction pathway. DAG acts as a second messenger that activates Protein Kinase C (PKC) and IP3 helps in phosphorylation of some proteins.
[edit] Function
Gq proteins are class of G proteins which work to activate phospholipase C (PLC), participating in a varity of cellular signaling pathways, including taste, manic depression, tumor promotion, etc.[1]
The Gq protein works by activating PLC. PLC then cleaves a phospholipid. In the process, phosphatidylinositol 4,5-bisphosphate (PIP2) is cleaved into diacyl glycerol (DAG) and inositol 1,4,5-triphosphate (IP3). DAG remains on bound to the membrane, and IP3 is released as a soluble structure into the cytosol. IP3 then diffuses through the cytosol to bind to IP3 receptors, particular calcium channels in the endoplasmic reticulum (ER). These channels are specific to calcium and only allow the passage of calcium to move through. This causes the cytosolic concentration of Calcium to increase, causing a cascade of intracellular changes and activity.[1]
- Further reading:Calcium function in humans
In addition, calcium and DAG together works to activate PKC, which goes on to phosphorylate other things, leading to altered cellular activity.[1]
- Further reading:function of protein kinase C
[edit] Examples of GPCR partners
From modulatory neurotransmitter receptors (amine receptors belonging to rhodopsin family), Gq is usually coupled to e.g. the G-protein coupled receptors:
[edit] See also
[edit] References
- ^ a b c Alberts B, Lewis J, Raff M, Roberts K, Walter P (2002). Molecular biology of the cell, 4th Edition, New York: Garland Science. ISBN 0-8153-3218-1.
[edit] External links
